I can make 30mm and 25mm roughly compatible but 40mm is too big for me. I always told my wife that those fantasy games have the advantage that all the minis are mutually compatible.

Actually, from their FAQ: Humans are 32mm at eye level.

So that'd be the normal Heroic scale, right?

32mm to the human eye is what is called the 32mm scale."Heroic" scale has little to do with height, but with height/width/features proportions.HQ and traditional Citadel minis are heroic scale, most contemporary minis are not.

Im really hoping to see them get to dwarves for stretch goals. The rats dont interest me much but dwarves would. Plus the orc minis look great. Much bigger than hq orcs but orcs always seemed like they should be bigger than humans in my mind which these would be.